


Lending a Hand

by skele_smol



Series: One dick, two dick. Red dick, blue dick [1]
Category: Undertale (Video Game)
Genre: AU, All the Sin, Anal, M/M, NSFW, Oral Sex, PWP, Porn, Puns & Word Play, Sanscest - Freeform, Smut, Surprise! internal handjob, Universe Crossing, ecto-cocks, handjobs, ketchup/mustard - Freeform, kustard - Freeform, literal fucking yourself, plot? who needs it?, sacrum sucking, sans/sans - Freeform, self-loving, selfcest, sin - Freeform, skele's with added peen, so much sin, spot the kinks, terrible puns
Language: English
Status: Completed
Published: 2016-11-20
Updated: 2016-11-20
Packaged: 2018-09-01 04:40:24
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 6,217
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8608363
Author URL: https://archiveofourown.org/users/skele_smol/pseuds/skele_smol
Summary: When the Papyrus are away, the Sanses can play.
A seldom night to themselves leads to the inevitable screwing in shared spaces. Sans shows Red a few new, neat tricks,and Red... well he has his own trick up his sleeve.Either way this is all smut. Don't like literal self fucking? This is not the fic for you.





	

**Author's Note:**

> Oh, hi there.
> 
> This is a first time Undertale fic. Possibly the first in a small 3 fic series. I warn you now that I haven't written anything, smut or not, in almost 5 years so I'm fairly rusty.  
> This thing came about from a chat with my friend and co-sinner on tumblr, which lead to ideas for me and playful threats from her lol. Her encouragement has been amazing and helpful and I love her for it.
> 
> Anyway, this is shameless self indulgent of my kinks. I hope it caters to yours as well

 

**Lending a Hand.**

 

 

Slow.

Frustratingly... infuriatingly...

_So. Fucking. SLOW!_

 

Flickering images from the forgotten television bounced their light from a single canine, a flash of gold slicing through the dim of the room as wide jaws clenched, caging his frustrated snarl behind his sharpened teeth.

_Why was this happening so slowly?_

It hadn't started slowly. A quick text message followed by a deep and throaty “s'jus us fer the night now” as Sans tossed his cell lazily back onto the coffee table beside his slippered foot. An arm slid around Red's shoulders and drew him down against the barrel chested him in this universe, “shot undyne a 'thanks' fer convincin' the paps t'catch a late screenin' with her an' alphys. an' t'have 'em crash at theirs, seein' as gonna be a late night an' all.”

His hand had trailed over Red's clavicle in a lazy and drifting path, but the touch was firm and drew excited shudders of anticipation from the slightly smaller skeleton. This was not a completely unexpected turn of events for an evening with the younger siblings conveniently gone though ,right now, it reeked of being a _scheduled_ and organized circumstance. Sanses were not known for their organization skills.

Hell, Red had even noticed that Sans' wussy pet rock was conspicuously absent from it's usual spot on the side table, though the colourful sprinkles remained.

Red pressed himself up and into the touch with a low rumbling groan of approval. Hell, the guy was trying, might as well show his efforts were appreciated even if it would simply be for a quick screw or two, maybe a lazy hand-job between naps as well.

However, the sound suddenly snagged in his throat when a conjured tongue trailed the length of his jawline. That was more... unusual. Kisses yes, Sans loved all that lovey-dovey crap, licks and -dear _christ,_ that was definitely the scrape of teeth too- nips were more Red's speed.

He had barley even cocked his face toward his counter-part and gave him a measured look, unsure of Sans' intentions as he read the warring of wants that were clearly exposed to him before he realized his assumptions of where this night was headed were wrong and his own confidence withered. He was granted a moment, but only a moment, to collect thoughts once more as Sans' own internal conflict resolved itself before teeth and tongue assaulted him with renewed confidence. 

Red's breathing hitched in his chest as blue magic snapped and popped in the air around him; heavy and cloying like the promise of a summer storm. Buzzing lightly over his bones and following the trail of Sans' touches, toying and crackling against his own magic. While the voice of Sans' soul sang to his own, coaxing and simpering for its attention, for its returned affections. He sighed and parted his sharpened teeth in response, only for his voice to catch in a surprised yelp when he found himself flipped with his cheek crushed into the well worn couch. 

Red squirmed and wriggled, pressing his face deeper into the darkness as he clawed the lumpy pillow that Sans was hastily shoving under his head with a rumbled _'fer yer comfort',_ and his expectations for tonight soared.

It was so much easier to start something intense without the Papyrus double act around. Between the overly loving nagging of Sans' Papyrus or the outright snarls of disapproval from his own, nothing killed the mood faster than having the two lanky skeletons pottering around. And Sans so rarely indulged in his rougher, kinkier side, opting more often for quickies in moments of opportunity and sudden bursts of energy. So for Red to find himself pinned under the other monster as he toyed with him, fingertips skipping merrily along his spine, his soul shivered and vibrated and cried in its delight.

His red magic flooded his bones, chasing the sensations of Sans' touch as it dipped and snagged and dragged the waistband of his shorts away, leaving him exposed and shivering under the longing gaze that flickered blue.

“hmm,” Red felt the rumble of words reverberate through him as Sans leaned closer, draped over him, his spine rolling down as it took Sans' weight so he could press his teeth along his vertebrae in fluttering skeletal kisses that drifted lower. “well now, look atcha curve tha' spine fer me. all nice an' pretty.”

Sans' distal phalanges scraped upwards along Red's inner femur, bone on bone, as his other hand slid along Red's sternum, ignoring the fluttering sob of the soul that slowly saturated red, housed behind the cage of bone.

“ya look so good when ya squirm.”

Red pressed his face deeper into the pillow, stifling the desperate whimper and hiding the high flush of red magic staining his cheeks. He loved it. The easy praise Sans worked into their intimate moments turned him on faster than he liked to admit. His soul pulsed, sending magic coiling through his bones, tingling and rolling down to pool into his pubic arch.

“only time ya look better,”

_Fuck._

Red could feel the conjured tongue sweeping along his sacrum, shallowly dipping into each hole as the moving fingers swept around to the outer side of his upper femur to press into the flare of his ilium spine and forcing him deeper onto the probing appendage.

“s'when yer squirming under me.”

That was when Red's brain suddenly shorted and his soul keened in anticipation as both Sans' hands swept and gripped into his hips, hoisting him backwards as teeth parted, scraping and catching along the sacrum as his entire tailbone was swallowed down. Red howled and wriggled and bucked; and still Sans held on, mouth working and tongue pressing, rubbing and dipping. He could feel Sans snickering around his full mouth, could feel the smirk stretched against him as he was worked. And he could feel his own magic solidify between his legs into a hard, twitching length. “fuck...fuckfuckfuck...ffffffuuuuh!”

His legs spasmed. Kicking out as best they could, scrabbling for something to push against and escape Sans' tongue as it traced the dips and grooves, probing with the tip and rubbing with the flat. Humming in contentment Sans managed to easily roll with Red's struggles, even going so far as to add lewd slurping sounds to his torment. And then, when his hand moved to squeeze a light fist around Red's cock, sliding down and twisting back up, Red felt his resolve snap through the fog of lust shutting down his brain. Red's face thumped back into the pillow, vision blurring as his eye sockets screwed shut against the tears threatening to spill at the stimulation. His fingers clawing into the old fabric, shredding it, teeth ripping into the fibers as he sobbed out piteous pleas.“t-too... mu- _hah!-_ huch! to- _ooooh_... f- _aha_ -st!”

He had begged Red to try it once before, grinning in delight when he had discovered just how responsive Red was to sacrum fondling. How he cooed gentle praise and encouragement as Red had all but fallen limp beneath him the first time Sans had taken his tongue and teeth to him. Eyes on his the entire time. Red had wept through the first experience, overwhelmed by the sensations and with his hands clasped over his mouth in a futile attempt to muffle his cries. He had been left a shuddering and mewling mess, ribs painted with his own release and left shivering and limp with the intensity of it all. And afterwards, when Red had buried his face under Sans' jaw he had begged that they take it slower next time, taking comfort in the soothing and nuzzling and that Sans had smiled _that_ smile at him. That roguishly charming curl of his mouth, lop-sided and confident  as he had _promised_ that they would.

Sans knew he was pushing the other monster to his limits! That grinning fucker _knew!_

Heat was coiling low in Red's groin now, tightening in his non-existent gut. The energy crackled as it lined his pubic inlet, ready and fluttering, clenching around nothing impatiently waiting to be filled. His struggles had weakened to little more than token twitches as his body shut down its flight and fight instinct and braced for the impending torrent of orgasm. The shredded pillow beneath his cheek absorbed the tears tracking along smooth bone as valiantly as its ruined form could as Red clung to it with one hand, desperate for something to ground himself with as his other reached for the fingers that ringed his cock...

He was so close now. So. Damned. Close!

A sob of surprise hiccuped over Reds clenched teeth. The hand around him was gone. He curled his spine down curiously. The mouth around his sacrum was gone. With a snarl of frustration he flopped flat on the couch beneath him, yanked the tatters of a pillow over his skull and did his best to ignore the throb of disappointment that vibrated through his magic and baleful cry of his soul as twisted in his chest.

“ya doin' okay, red?”

Sliding a single red eye light over to where the voice sounded from, Red sent the best attempt at a withering glare he could muster.

“oooh, scary!” Sans chuckled. Dropping a water bottle directly into Red's reach. “here, ya need t'keep hydrated. night's jus' startin', buddy boy.”

“fuck you!”

A snort from behind as Sans flopped himself back on the couch. “nah, s'not what i got in mind fer t'night.” Drinking deeply from his own bottle before nudging the second one closer to the sprawled out monster beside him. “seriously though, drink up.”

Huffing Red snatched up the water bottle, drank down the entire contents in a few quick pulls before flopping face down again and tossing the empty bottle in the vague direction of the coffee table. “there! happy now?!” He felt hollow. Dissatisfied and unfulfilled, the magic that fueled his arousal, fueled his dick, already dissipating with a disappointed buzz.

He had expected the chuckles that fluttered flirtatiously around him, had expected the sound of Sans' bottle bumping onto the coffee table after he had drank his fill. But what he hadn't expected was the dark whisper purred directly against his skull as a knee shoved itself up against the not-quite-gone magic still gathered along his pubic joining. “be happier when i'm balls deep in ya.”

_oh, fucking fuck!_

Red felt his soul instantly lurch and flutter behind his ribs at the words, leaping and crying like a rabbit trapped in a snare. His voice caught in his throat when the cushions behind him dipped and a second knee pushed between his own, sending his outside foot thumping to the floor for balance as a firm grip hauled him roughly back onto his hands and knees. Sans' magic, still clothed, crammed up _hard_ against his awkwardly tilted pelvis, resting against his still thrumming sacrum. Though it was shapeless Red shivered beneath the familiar weight of blue magic, relished in the heavy and hard promise of a cock he knew to be satisfyingly thick. He whined and pressed back against it, wriggling for friction of any kind until hands gripped him still and held him steady, just barely twitching against him in maddeningly slow and shallow thrusts.

“god _fucking_ dammit, sans!” Red snarled and circled his hips, trying to angle himself so that Sans would... just... _slip_... and press where he wanted to finally feel him. But with every shift he made Sans escaped it. When he pressed back, Sans retreated onto his haunches, when he ducked Sans weaved, if he arched higher he was simply pushed back down and held still, the heat of blue magic buzzing just barely above him. “either fuck me or don't! i jus... so done with this teasin' bullshit!”

“s'not... yer call, _boss_.” Sans panted, ducking his mouth down to trail the flat of his tongue a single, final time over and under Red's sacrum before shoving a hand down to his own waistband and hiking his shorts just low enough for his magic to spring free. Wisps of soft feathery silver  blue glow spread from the white soul under Sans' ribs, coiling together and darkening as it traveled, thickening and fleshing out his sex until it bobbed against the squirming monster beneath him. “s'my little game, r'member?” he chided. “ya jus' gotta play it by _my_ rules. s'all i'm askin'.” 

Sans rolled his hips, his cock smearing pre-cum along Reds femurs, nudging up against the underside of the coccyx before barely parting the humming red magic lining the pelvis beneath his hands. Leaning up, Sans smoothed a hand up under Red's T-shirt, bunching the fabric at the base of his skull. Nipping and licking a path up to his shoulders and pressing the thick head of his cock just past the resistance between Red's thighs, careful to stifle the contented lilt to his voice at the tight warmth squeezing around him. “jus' lemme take care 'o ya.”

Red barked a sharp but approving sound, his frustration finally evaporating at the feel of the comforting burn that Sans' soul pulsed through his magic as it squeezed through the opening into his pelvic inlet. Thrumming its own distinct rhythm inside him and humming around his own crackling magic, warmth and sensations seeping deep into his bones. He tucked his chin to his clavicle and gazed longingly down the length of his sternum, mouth curling up on one side as he glimpsed the swollen blue head wrapped snugly in red magic and framed gloriously by his iliac crests. It was almost perfect, all he needed was a little more. He just needed Sans to seat himself deeper, so he could watch his magic stretch and accommodate that thick cock, gripping it tight as he milked it with every thrust.

He wanted Sans to let loose. Hold him down. Fuck him raw. Coat him from the inside out. And he wanted to watch every last stuttering, messy second of it. Emboldened by his lust Red eased his hips back, mouth spreading wide as he heard the long, low moan behind and above him, smirking in satisfaction as he took Sans deeper...

… right up to the point that he felt hands slap down hard on his pelvic wings and roughly shove forward again, until the wonderful filled feeling threatened to leave him entirely.

“uh,uh,uh. not so fast there, buddy boy.”

His eye lights swept up until he was peering up awkwardly from beneath his arm, vision fizzing and popping with dancing colours as he strained to focus on Sans' face. If he didn't think it would look so damned ridiculous with him laying prone and pinned beneath the other monster with his cock parting him, Red would have attempted to throw a temper tantrum. Instead he simply lay still, scowling up at the mock disapproving look on Sans' face. Just as he opened his mouth to spit insults, he felt the press and drag of Sans' hips, driving his cock forward in a slow, shallow, perfectly controlled thrust.

“i told ya.” A slow press forward. “this's my game,” An equally slow drag back. “so my rules.” A barely there roll of his hips just to drive his words home. “got it?”

Red stubbornly clamped his jaw and turned his face back into his shredded cushion without saying a word. Like hell he was gonna stroke Sans' fucking ego by agreeing with him. Bad enough that the bastard had him pinned, had gone down on him and fucking _edged_ him. Now he was demanding that Red play nice just so he could enjoy his power kink. No fucking way that shit was gonna happen. No sir-ee!

No, Red was going to simply lay here and let Sans wiggle his cock a bit, get them both off and then he would slap the permanent shit eating grin off his fucking face and call it a night.

But this slow, shallow shit wasn't going to get him off. Well, not on it's own. Smirking, Red shifted just enough to free one hand and reached between his spread legs. His fingertips brushed along his own thrumming cock before he tunneled his fist around it and stroked firmly, eliciting a strained sigh from between clenched teeth as he shuddered from the stimulation he'd so desperately craved.

A low and drawn out moan rumbled low in Red's chest as he stroked himself faster. Toe-curlingly fast. His grip almost brutal. His sharpened teeth bit down on the knuckles on his other hand, choking back the cries of relief bubbling up his throat. His eye sockets shuttered in bliss as he twisted his wrist and switched up the angle. Zeroing in on the tingling that began building at the base of his spine and chasing the sensation until he felt his body jerk and he snapped up like a whip as Sans bottomed out in him. Using the moment of surprise, Sans reached around and grabbed Red's wrist, tugging his hand away before his hips retreated again, his magic slipping out of Red completely. 

Throwing a glare over his shoulder, Red grabbed and tried to pry Sans' grip from his wrist, scrabbling at the encompassing fingers until Sans' other hand shot out and Red found both his arms twisted up behind him as Sans, in an impressive display of agility and balance, spun them around and slammed Red's front up against the back of the couch. Wedging his knees inside of Red's and spreading them wide, Sans husked against the back of Reds skull, voice warm and dark but his tone almost threatening. "caught ya!"

Red snarled and twisted against Sans' hold, only to feel the other skeleton apply a firmer pressure to his twisted arms. Not enough to hurt but enough to prevent Red from wanting to risk moving too much. As his captive relaxed against the cushions again, Sans slid his hips forwards, swollen head nudging deeper into the pelvic inlet once more.

 "caught?" Sans demanded, and again Red fought. Smirking, Sans simply lifted his body from Red and let him thrash until he pressed on the arms again, always careful not to hurt. “t'fuck's gotten inta ya, red? s'like somethin's crawled up yer ass an' set up camp-”

 “yeah,” Red felt a flash of outrage that far out stripped his previous flares of temper as he grated his words from between his teeth. “ that would be you, asshole!”

A low, throaty chuckle mocked the wilder version of himself as Sans shifted his grasp on Red's wrists, gathering both into one hand. “this? this's jus the _tip..._ of what i got in store fer ya.” Reaching around and grasping the other monster's length with his newly freed hand, he gave a single firm stroke. 'but dun' ya worry 'bout it, i ain't 'bout t'leave ya feelin' _shafted._ ” He grinned, feeling the other skeleton buck in his grasp, but when Red still refused to voice his moans, Sans slipped his thumb over the slick and reddened tip, stroking in tiny circles. Teeth grazing over Red's nape, mouth rumbling as he teased the line of his jaw before he gave a sharp squeeze to the magical appendage in his grip. "tch. st'born bastard."

A cry caught in Red's throat, and he tried his damnedest not to voice it, but the first note had passed his teeth before he thought to stop it and he felt the mouth roving his mandible pull back into a smirk. “atta boy. sing fer me.”

Red screwed his eyes tighter and flinched when thick fingers left his cock and caught his chin in a grip that was firm and scarcely shy of painful as Sans angled his head around; tipping it over his shoulder as much as he dared without hurting him, forcing Red to rear away from the couch's back and fall against him. Bared teeth moved against the side of his mouth in comforting skeletal kisses, Sans crooned softly, as though dealing with a difficult child's tantrums. “yer'd like it more if ya jus' relax.”

Chin still gripped and held tilted over his shoulder, Red squirmed as a flash of frustration hardened his eyes and he scowled awkwardly at his counter-part. “i'd relax more if ya'd just fucking _fuck_ me already!”

Sans watched wordlessly, hips still pressing shallow and slow thrusts up into the slightly smaller skeleton caught tight in his grasp. He watched carefully as flickering red eye-lights softened and dark sockets slitted in mounting pleasure. He groaned softly when Red's mouth awkwardly crushed against his in a sloppy response. His teeth parting and a faintly glowing tongue probed at Sans' own teeth, tracing and licking until they responded and granted entrance.

The sudden submissiveness of the move startled Sans for a moment, before he sank into the kiss and he gently pulled on the trapped arms in one hand, wordlessly coaxing Red to settle back a little over him. Blue magic nudging into the pelvic cradle once more, stretching and wrapping itself in the red magic a little deeper.

The new position was awkward to maintain with Red's arms twisted and held against his spine. Sans was struggling to hold the other monster down and keep his balance kneeling on the edge of the couch. With every roll back his gut would flip-flop with the sensation of falling backward, which he would then hastily try to balance by a too sharp a jerk forwards, his chest hitting into the back of Red's ribs with a force that sent him sprawling over the back of the couch cushions and himself deeper inside red than he intended. After his third near tumble Sans huffed his irritation and simply let go of his grip on Red's wrists. Immediately the other skeleton drew his arms beneath his chest, pushed and twisted himself enough to peer over his shoulder, suspicion obvious in the way the one visible eye-light constricted and the fathomless darkness around it narrowed.

“yer right not t'get complacent. ain't a free rein t'do as ya please, buddy-boy.” Sans snickered and slid his hands down over Red's hips, stopping either side of his coccyx and forming a sort of seat. Sans tucked his elbows tightly to his sides and locked them, preventing Red from thrusting back to meet the shallow pumps of the hips below, a reminder that he was still very much in control of the situation.

“don't go tryin' t' _push_ yer luck, t'ain't gonna get ya very far.” A slow, firm press forward had Red immediately testing the new instruction. His own hips reflexively rolling downwards, intent on pushing the new boundaries and chase the teasing cock beneath him, his throat eliciting a tight snarl of outrage as the seat of hands thwarted him.

“i warned ya. ain't gonna work.” Teeth and tongue latched onto the underside of his mandible, teasing and flicking for a moment before it drew just far enough back that he could feel Sans' panting breath skimming his neck with every half thrust.

Red let his head drop forward, resting against the couch back, forcing himself to simply focus on the sensation of Sans' cock pressing in the couple of inches before dragging out again. Focusing on the stretch and burn of his magic, watching as the blue forced the red outwards with every intrusion and how the red sprang back into place as blue retreated, chasing back the thick... swollen... head-

He was so fucking _stupid!_ How had he not realized this earlier?!

Sans' shallow movements. The position Red was held in... Sans wanted friction. His slow and shallow rolls were testing for the angle he wanted. Red watched a few moments longer, listening to the bitten back curses behind him as his mind conjured an interesting thought. If Sans wanted more friction, more snugness, maybe, if his idea panned out he could give the other skeleton that. Carefully he reached his hand down between his legs, ignoring his own cock as he moved lower.

A dark warning growl halted Red's progress. “i told you. _no... touchin'_!” The rich timbre of Sans'  usually steady voice fractured in a high whine, his hips maintaining the still too slow, too shallow rolls. Clearly he was still not content with the angle or the grip that surrounded him.

“'m not.” Red snarked back. Fingers skimming down -but not touching- the inside flare of his pelvis, shivering as the joining magic crackled up over his hand, seeping its warmth into the marrow of his delicate carpals and reaching for his touch. Drawing him closer and cushioning the strain of the awkward angle as he delved inside himself, finding Sans wrapped tightly inside his red magic. “'m touching _you_!”

He gave a firm squeeze only to be suddenly jolted forward, thrown off balance. But instead of finding himself thrown back onto his hands, Red felt Sans anchor him, fingers twisting into his lower ribs and teeth sinking into the side of his neck hard enough to elicit a sharp cry of pain and for him to instantly release his grip of their joined magic.

“don't!” Sans rumbled low in his throat. Dragging his tongue over the fresh teeth marks, soothing the sting and pressing his mouth against the side of Reds skull, his growls fading to breathy pleas. “don't. stop. jus'... jus' keep doin'... jus' like that-” His hands came up, sliding under Red's arms and folding up to grip his shoulders as he finally, _finally_ , seated himself completely inside. “-please.”

Red's soul lurched at the under tone of desperation in Sans' voice, the cracks in his carefully maintained facade widening with every full thrust. He was nuzzling, nipping, teeth and tongue trailing along Red's mandible, his breath hot against the damp lines the blue appendage drew. Red smirked softly to himself, chin lowering to watch for a moment as the blue length moved in steady strokes, pressing hard against the thrumming walls of red magic. This is what he wanted to see. He wanted to see himself spread wide, stretched tight around Sans. He wanted to hear the breathy whimpers, the broken curses, his _name_ tumble from the other him's teeth.

He reached back inside his pelvic cradle, fingertips pinched the red magic tight over the intruding blue. And the reaction was immediate. Sans' hips stuttered under him before one hand dropped down along his arm, gripping his wrist before winding the arm around his neck. Confused, Red tilted his head over his shoulder and found Sans' sockets at half-mast, the usually bright eye-lights clouded with a lust he had never seen before they drifted down and then zeroed in on the tip of his red tongue held between sharpened teeth.

Sans ducked in; teeth parting and his own tongue pressing between Red's, dominating and twining around his mouth, between his teeth and along his jaw. Licking and tasting and messily chasing the others tongue and swallowing every whimper and whine. Red's hand tightened in reflex on the joined magic, finally fisting around them with a grip that had Sans' head wrenching backwards in a strangled howl. Magic crackled and snapped along bones, heavy and sweet as it raced through them, humming and stinging both skeletons souls with sensations that almost shorted out Red's brain.

“fuh-haa... fuck! tight... squeeze tighter!” Sans breathed against Red's teeth. His fingers wrapping around the fist, showing Red exactly how he wanted it, squeezing until his hips jolted forward and his hand shot back to grasp at Red's hip, grinding and grounding himself with a ragged pant, his other hand flexed on Red's shoulder. “jus' l-like tha- _aha-_ t.”

Red whimpered brokenly. Straining to keep his balance as Sans moved harder inside, his wrist aching from the awkward angle it had working his own magic over his counterparts. His femurs burned under the prolonged strain of being parted so wide for so long and yet his body sang with the raw, unbridled lust. He could feel Sans everywhere on him, inside him, filling him. He could taste the unique flavor of blue magic through his own, could hear it singing around him until he could scarcely hear Sans vocalize his desperation anymore.

“ _cl-oooohh-_ se... 'm close. so close.” Sans whined directly against the back of Red's neck. Fingers tightening on his pelvic crest as finally, _finally_ , Sans' control broke as he slammed Red down and stabbed himself upwards so hard and deep that Red swore his pelvis would crack and he could feel the desperate throb of magic in the back of his throat.

Red threw his head back against Sans' shoulder, eyes closing as the sensations threatened to overwhelm him. His pants ending with a hint of voice, his own orgasm building but he just wasn't quite there. Red's arm, the one that Sans had wrapped around his neck so Red could anchor himself once he had started fucking him in earnest, began to slide free and drift down to finally touch his own neglected, weeping cock. Only to have Sans grip the wrist and wind it back around his neck.

Red could have screamed his frustrations until Sans' stuttering voice almost tipped him over the edge.

“do- _ooooh_ -n't.” he panted desperately, hand gripping Red's iliac crest once more. “watch me - _haaaah_ \- watch me come in ya.”

Red's chin dropped to his chest, eyes sweeping down his shuddering form, watching through a half-lidded gaze as Sans pumped through his tunneled fist as well as his magic. His own length, swollen and dribbling, bobbed wildly with every thrust. He felt the pelvis beneath him shudder. Heard the deep, dusky voice break and tremble.

“let _g-oh,_ red. lemme go- _ooooooh!_ ”

He obeyed, letting his grip go slack before twisting into his shirt and hiking it under his chin, completely baring his ribs as Sans threw his head back and howled, hips pumping as deeply and furiously as he could manage throughout his release. Red watched every spurt with rapt attention as blue residue mingled through his red, painted his pelvis, his femurs, his lower ribs. His jaw hanging slack and relishing in the sensation of the other skeletons' release yet he couldn't stop the soft rumble of disappointment in his throat.

The rumble turned to a sharp gasp as he felt a shaky hand wrap around his cock, head swinging round to meet with a weakly grinning but incredibly satiated face.

“'m not 'bout t'leave ya _blue ballin'_ now, red.” Sans squeezed firmly, eliciting a hiss from Red. “what kinda bastard d'ya think i am?”

Red opened his mouth to retort but all he could utter was a strangled moan as Sans rolled his fist, squeezing on the up pull, twisting around the head before sliding back down, test stroke before Sans flexed his fingers, adjusted his grip and began to pump furiously. His pace was brutal, his technique punishing. It was about all Red could manage, to simply cling on for the ride, his fingers twisting deeper into his shirt until the fabric groaned under the strain.

Despite his own climax Sans' magic hadn't faded, his hips still rolled under Red, timing each upward thrust with the down slide of his fist. The strong twitching around him from still being buried inside Red had his toes curling with a new buildup of pressure, drawing a final wave of his exhausted magic down into the base of his spine.

He nuzzled where Red's ear may have been had he flesh and murmured gentle encouragement and praise, injecting the cooing and coaxing with dark growls of filth that had Red squirming in his grasp. Torn between chasing Sans' hand as it slid away and pressing back to milk the magic still impaling him, Red fell into an awkward and uneven rhythm.

“atta boy, red. s'what I wanna see. ya fuckin' yerself, fuckin' my fist.” Sans purred, fist gliding faster over the others cock. “ _fuck!_ i wish ya could see yerself, hear yerself. y'look so good spread like this.”

Red felt his voice crack in a low moan. He was almost there. He had never been worked so hard, so thoroughly in his life. Held teetering on the edge for so long that he felt every movement drawing him closer to that edge where pleasure bordered on pain that he couldn't be sure if he wanted to finally fall over the edge or give up and beg Sans to stop. Unsure if he was going to hold himself together and ride out the torrent or shatter into a desperate sobbing mess.

“tell me what'cha want.”

“ _hah!_ i want...”

He didn't know anything except that he was close...

“i _wa-hhnnna..._ ”

“yeah?”

Teeth grazed over his skull, fist pumping and that tight ball of sensation that had been building low where his belly would be. Simmering and lancing his spine, setting his sharpened teeth on edge as it pulsed threateningly. Coloured smudges danced into his vision as he screwed his sockets tight. So close, he was almost...

… _Almost..._

His mind sharpened as his soul screamed the decision for him.

“ _fuck!_ sans... i wanna come!”

“then come.”

Red's head fell forwards, brow pressed into the back of the couch, the bony ridge furrowing over scrunched shut sockets and his gasps tugged at his chest. “fuck... _oh fuck_! sans!”

“tha's it! leggo red, yer there! _fuck, yer there!_ ” Sans' voice hitched as he coaxed. Red's magic clamped down on him _hard_ as he finally broke. Hips dropping down, burying Sans deep as Red bucked and spasmed and howled, his release splattering the couch cushions, and dribbling in strong pulses over Sans' fist and his own femurs.

Sans fell forwards against the other him, pinning the exhausted monster between his ribs and the now ruined couch cushions as the convulsions around him coaxed a final exhausted spurt of his own magic from him before the drained blue faded and dissipated. He trailed the tips of his fingers over and along the trembling form beneath him, beaming with pride because he could feel Red's soul _still_ quivering inside the cage of bone and marrow. Fluttering and trembling wildly despite the sudden fading of Red's magic. Sans felt his brow bone slope down into a soft frown of concentration as he focused his senses onto the souls voice. It trilled and sighed and praised him as soon as it felt the comforting voice of Sans' blue magic reaching toward it, stroking away the concerns and reassuring that it was not damaged as red magic coiled blue closely around itself and pulsed steadily.

Satisfied with the reaction Sans simply basked in the satisfied glow of the other him, until he felt Red stir and press back against him, grumbling at him without the usual bite to his words when Sans refused to move. “fuck's sake, sans get offa me.”

“awww, but yer comfy.” Sans barely stirred, pressing his teeth gently to the side of Red's skull, breathing softly as he murmured lazily. “should ya be tryin' t'move right now? uh, i mean, ya good, right?”

Red shifted, freeing up a hand so that he could reach up over his shoulder and knock his knuckles gently against Sans' temple. “yeah, 'm good. jus' need you to get off-”

Sans turned his face to nuzzle the loose fist, chuckling low and soft. “again?! shit red, ya tryin' t'kill me? Don' think i got 'nother one in me.”

A low groan, followed by an elbow to the ribs left Sans wheezing as Red wriggled free. Sans rolled himself to a sprawl, parting a single socket, watching Red stumble to his feet, his soul swelling with a primal sense of pride at the sight of the red and blue residue mingling on Red's bones, sliding and dripping sluggishly off his ribs and pubic joining.

'y'know, th' pap twins r'gonna shit a brick if ya drip all over th'place like that.” Sans called, his brow wiggling mischievously.

Red sighed and rolled a soft glare toward Sans as he bent and hiked his shorts back up over the mess on his bones. He flinched as he felt the cooling magic smear, it wasn't pleasant but it would have to do for now until he could get himself into a hot shower and rinse off. Turning on his heel, Red strode from the room with as much dignity as he could muster on wobbling legs, ignoring Sans' laughter as he stumbled into the hallway until he called back over his shoulder in a haughty a tone as he could manage. “don't you think they might shit a few more bricks over the state of the couch?”

“th'state of the...” A beat of silence as the pin dropped and Sans caught onto Red's cryptic retort. “awwwww, friggin' hell-”

Red sucked a breath in between his teeth and chuckled softly to himself, imagining Sans frantically trying to clean up the magic seeping into the couch fabric, while desperately trying to think of an excuse for the damp patch when the brothers returned in the morning. Still chuckling, Red began shuffling up the stairs and headed to the bathroom-

 

-yeah, the evening had started off slow... but it finished with one hell of a bang.

 

 

 

 

 

 


End file.
